The third film. Eleven Oscar wins on eleven nominations — tying Ben-Hur and Titanic for the all-time record.
Aragorn rallies the men of the West and rides the Paths of the Dead. Gandalf and Pippin race to Minas Tirith. Sauron's armies besiege the city. Théoden leads the Rohirrim to the Pelennor Fields. Éowyn slays the Witch-king of Angmar. Frodo and Sam, on the eastern side of the Mountains of Mordor, climb toward Orodruin, with Gollum following.
The film delivers on every promise the trilogy made and then refuses to end on the volcano, because Jackson and Walsh and Boyens understand that the cost of victory is the actual subject. The Scouring of the Shire is omitted from the film, but four separate epilogue sequences carry that emotional weight.
The Battle of the Pelennor Fields is the largest battle sequence ever committed to film up to that point. Massive Software, the AI-crowd system Weta Digital developed for the trilogy, simulated 200,000 individual soldiers with their own behaviour. Jackson shot the practical foreground — Théoden's speech, the cavalry charge, the Mûmakil — over weeks in New Zealand.
The Rohirrim charge — 'Death! Death! Death!' — is the single greatest hero-arrives-on-battlefield moment in 21st-century cinema. Bernard Hill's Théoden delivers Tolkien's speech almost unaltered.
Return of the King has been gently mocked for its sequence of endings: Mount Doom, the eagles, the coronation of Aragorn, the hobbits' return to the Shire, Sam getting married, Frodo writing the book, Frodo leaving for the Grey Havens. There are roughly twenty minutes of denouement after the climactic action.
This is, in fact, the right structural choice. The trilogy has spent ten hours making you understand that the Shire is what's being fought for; cutting away the moment the Ring is destroyed would be a betrayal of the films' premise. Jackson is one of the few major Hollywood filmmakers who understood that the third act of a fantasy epic is the homecoming, not the battle.
Return of the King won every Oscar it was nominated for at the 2004 ceremony: Picture, Director, Adapted Screenplay, Score, Song, Editing, Visual Effects, Sound Mixing, Art Direction, Costume Design, Makeup. No film in history had won eleven Oscars on eleven nominations before; only Ben-Hur (1959) and Titanic (1997) had also reached eleven wins total. The Academy retroactively recognised the trilogy by giving Return of the King essentially every available technical Oscar.
It is the only fantasy film ever to win Best Picture.